/*
 * All content copyright Terracotta, Inc., unless otherwise indicated. All rights reserved.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 
 * use this file except in compliance with the License. You may obtain a copy 
 * of the License at 
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0 
 *   
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 
 * License for the specific language governing permissions and limitations 
 * under the License.
 * 
 */
package org.go.matchers;

import org.go.util.Key;

/**
 * Matches using an AND operator on two Matcher operands. 
 *  
 * @author jhouse
 */
public class AndMatcher<T extends Key> implements Matcher<T> {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1437368317039906629L;

	/**
	 * Create an AndMatcher that depends upon the result of both of the given matchers.
	 */
	public static <U extends Key> AndMatcher<U> and(Matcher<U> leftOperand, Matcher<U> rightOperand) {
		return new AndMatcher<U>(leftOperand, rightOperand);
	}

	protected Matcher<T> leftOperand;

	protected Matcher<T> rightOperand;

	protected AndMatcher(Matcher<T> leftOperand, Matcher<T> rightOperand) {
		if (leftOperand == null || rightOperand == null)
			throw new IllegalArgumentException("Two non-null operands required!");

		this.leftOperand = leftOperand;
		this.rightOperand = rightOperand;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		AndMatcher other = (AndMatcher) obj;
		if (leftOperand == null) {
			if (other.leftOperand != null)
				return false;
		} else if (!leftOperand.equals(other.leftOperand))
			return false;
		if (rightOperand == null) {
			if (other.rightOperand != null)
				return false;
		} else if (!rightOperand.equals(other.rightOperand))
			return false;
		return true;
	}

	public Matcher<T> getLeftOperand() {
		return leftOperand;
	}

	public Matcher<T> getRightOperand() {
		return rightOperand;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((leftOperand == null) ? 0 : leftOperand.hashCode());
		result = prime * result + ((rightOperand == null) ? 0 : rightOperand.hashCode());
		return result;
	}

	@Override
	public boolean isMatch(T key) {

		return leftOperand.isMatch(key) && rightOperand.isMatch(key);
	}

}
